Which Sources to Use
Table of Contents
- Academic sources
- Non-academic sources
- Non-academic sources that look like academic sources
- References
When you are preparing a writing assignment for a course at the university, you may receive specific instructions on which types sources you are and are not allowed to use, which sources to prioritise, or minimum or maximum amounts for (specific types of) sources to include. Always read the assignment instructions carefully, and follow them to the letter. Also remember that your assignment instructions will take priority over any advice given in these pages.
In general, we can broadly divide potential source materials for your writing assignment into two types: academic sources, and non-academic sources.
Academic sources
Academic sources are texts that have been published in official academic publication venues, and undergone a form of peer-review. They include:
- Peer reviewed journal articles
- Chapters in edited volumes
- Academic monographs
These types of sources have been vetted by experts in the field and can form a fruitful basis for your own critical thinking and argumentation. You will not be expected to justify your use of these sources in your narrative. Still, especially when a source you are using is particularly relevant to your research (and is perhaps discussed in more detail than other sources used), it can be useful to be precise when you first introduce it to your reader, and provide some relevant context. You can, for example, explicitly mention the publication venue and year if it seems relevant. When you are aware that a particular source is especially highly-cited or otherwise well respected in the field, it can be useful to mention this to give more weight to the source in your narrative, and show the reader that you are aware of the wider academic context in which the source circulates. In the same vein, it can be useful to highlight when you are citing the work of an especially well-established author in the field.
At the same time, you should be aware that each of these academic sources take a specific position in a larger academic discussion, and that even though they are peer-reviewed, they should never be taken at face value. These sources are always defending a case that you do not necessarily have to agree with. The expectation is that they build a sound argument for their case, on the basis of some type of data that was gathered using a combination of justifiable research methods. But these methods may not be relevant to your own case, and the argumentation may be more or less convincing. You may be able to find counterarguments to question their results, and especially in the case of older materials, others may have already done so before you (and published about it). This should inspire you to always take a critical attitude towards the texts you are reading, and to determine for yourself how relevant they may be to your own research. When you use your assessments of the validity and relevance of your sources to your advantage when you introduce and contextualise them in your writing, this will help convince your reader (and examiner) that you are a critical thinker with a voice of your own.
Non-academic sources
Non-academic sources are texts that have not been vetted by experts in the academic field. They include websites, policy documents, non-academic archive materials, blog posts, etc. When they are relevant to your research, you are of course welcome to quote and paraphrase them. But you should do so with moderation, and always make it clear, when you use and introduce these sources, where they come from. As a general rule of thumb, make sure that your reader never needs to look up a reference in your bibliography to find out that the source in question is anything other than a peer-reviewed academic source.
About referencing Wikipedia
Unless your research specifically deals with Wikipedia as a research object, avoid referencing the website in your academic writing assignments. Wikipedia is a community-based encyclopedia-like website, and has not undergone academic peer review. Anyone can contribute to Wikipedia, to add false information as well as true. Wikipedia requires authors to use and list references when they contribute to the website, and also boasts a strong community of moderators, who sometimes flag and fix issues in minutes after acts of vandalism have occurred. But these moderating communities are stronger in some corners of the vast Wikipedia resource than in others, and do not always catch everything. Wikipedia is also continuously edited, which makes it more difficult to use it as a stable and lasting point of reference – at least without deep-diving into the website’s versioning history. In most cases, information you might cite from Wikipedia can be regarded as common knowledge that does not require a reference, or could be found in and lifted from a more appropriate resource. You can, of course, use Wikipedia as a jumping off point, to help you find more relevant, reputable, and stable source materials.
About referencing video lectures and other training materials
Similarly, you should avoid referencing (video) lectures and other training materials offered in your university courses in your writing assignments. Lectures, video lectures, lecture slides, tutorials, canvas pages, etc. have not undergone peer review, and should not be confused with vetted academic source materials. In most cases, topics discussed in lectures will build on peer-reviewed research, published in more appropriate venues. Rather than citing the course materials, you are expected to do the work and look up how they fit in the larger discussion of academic literature (whenever it is relevant to your own writing, of course). The literature lists provided in class are usually designed to help you on your way to do exactly that.
Non-academic sources that look like academic sources
Some sources look a lot like academic source materials, even though they have not undergone the same rigorous peer-review process. Examples include editorials and introductions to journal issues and edited volumes, preprints, and other non- or pre-peer-reviewed research.
Editorials and Introductions
Editorials and introductions can provide useful context to the sources you are referencing. They can explain the scholarly impetus for an edited volume, or a journal’s thematic (special) issue, or a relevant conference that took place. They can explain the state of the art in a certain field, red threads throughout chapters in a volume, or interesting discussions that took place at a conference. All of this can be useful information to you, to help you understand the nuances of the larger academic discussion, and to share some of that knowledge, where relevant, to the reader.
When you do, and you paraphrase or quote these documents in your own writing, you should take into account that, valuable as they may be, they have usually not been peer-reviewed, and should be treated as the editors’ unvetted (albeit educated) opinions. As a result, when you do use these sources in your writing, you should always indicate what type of source you are referencing.
✨ Best Practice
As the editors of Variants 19 explain in their editorial, the 2025 issue combines extended versions of papers that were presented at the 2023 ESTS and GENESIS conferences with two spontaneously submitted essays (Dillen et al. 2025).
Preprints and other pre-peer-reviewed sources
Nowadays, scholars are often publishing their research in preprint repositories like arXiv.org before submitting them to a journal for peer review. This practice is especially prevalent in the (STEM) sciences, where the speed with which new developments and important discoveries are made conflicts with the slow process of peer-reviewed publication, with its checks, balances, and high dependency on academic volunteer work. But the practice is also increasingly used in the social and information sciences, and digital humanities.
When it is relevant to your own writing, you are generally allowed to use pre-prints and the like, as long as you make it clear in your text that the information you are referencing has not (yet) been peer-reviewed, for example by explicitly calling it a preprint when you first introduce the source. You should be aware, however that since this is not a peer-reviewed resource, it will also not count as one if you have a quota to reach for your assignment.
Because preprints have not yet been peer-reviewed, you should be especially careful when you paraphrase and quote their contents. Like with peer-reviewed materials (and even more so for preprints), you should never take the data and conclusions presented in the research at face value. You should also be careful not to rely too much on preprints in your writing. You should always try to let peer-reviewed research constitute the bulk of your reference list, and give more weight to peer-reviewed findings when you build your own arguments. Of course, there may be good reasons for allowing preprints to take up a considerable share of your referenced sources, for example when the research field you are exploring is so new, that very little relevant peer-reviewed research exists. In those cases, however, this should be clearly motivated in your text, and the sources need to be put in their proper context. In addition, you will also be expected to demonstrate a critical attitude towards you source materials; even more so than with peer-reviewed sources.
References
Dillen, W., Pereira, E., & Rosignoli, S. (2025). Editors’ Preface. Variants. The Journal of the European Society for Textual Scholarship, (19), iii–vi. https://doi.org/10.4000/15dof